U.S. patent application number 14/170139 was filed with the patent office on 2014-08-14 for microchannel heat exchanger.
The applicant listed for this patent is Trane International Inc.. Invention is credited to Stuart Allen Means.
Application Number | 20140224460 14/170139 |
Document ID | / |
Family ID | 51296650 |
Filed Date | 2014-08-14 |
United States Patent
Application |
20140224460 |
Kind Code |
A1 |
Means; Stuart Allen |
August 14, 2014 |
Microchannel Heat Exchanger
Abstract
A microchannel heat exchanger of an HVAC system may include a
plurality of microchannel tubes having fins disposed between at
least one pair of adjacent microchannel tubes. The pair of adjacent
microchannel tubes may connect a header on each end of the
microchannel tubes in fluid communication, and at least one of the
microchannel tubes and the fins are oriented substantially parallel
with respect to a primary airflow direction of an airflow across
the microchannel heat exchanger.
Inventors: |
Means; Stuart Allen; (Tyler,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Trane International Inc. |
Piscataway |
NJ |
US |
|
|
Family ID: |
51296650 |
Appl. No.: |
14/170139 |
Filed: |
January 31, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61762759 |
Feb 8, 2013 |
|
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Current U.S.
Class: |
165/173 ;
165/172 |
Current CPC
Class: |
F28D 1/05383 20130101;
F28D 2001/0266 20130101; F28F 2260/02 20130101; F28F 1/105
20130101 |
Class at
Publication: |
165/173 ;
165/172 |
International
Class: |
F28F 1/10 20060101
F28F001/10 |
Claims
1. A microchannel heat exchanger, comprising: a plurality of
microchannel tubes; and fins disposed between at least one pair of
adjacent microchannel tubes; wherein at least one of a microchannel
tube and a fin is oriented substantially parallel to a primary
airflow direction of the microchannel heat exchanger.
2. The microchannel heat exchanger of claim 1, wherein at least one
of the microchannel tubes is substantially flat.
3. The microchannel heat exchanger of claim 1, wherein at least one
of the fins is substantially corrugated.
4. The microchannel heat exchanger of claim 1, wherein at least one
of the microchannel tubes is oriented to carry refrigerant in a
direction generally transverse relative to the primary airflow
direction and further oriented to present a minimal footprint area
when viewed in a direction parallel to the primary airflow
direction while maintaining the orientation of refrigerant
travel.
5. The microchannel heat exchanger of claim 1, wherein a footprint
of the microchannel tubes is maximized when viewed in a direction
substantially transverse relative to the primary airflow
direction.
6. The microchannel heat exchanger of claim 1, wherein a footprint
of the microchannel tubes is minimized when viewed in direction
parallel to a direction in which the microchannel tubes carry
refrigerant.
7. The microchannel heat exchanger of claim 1, further comprising
headers that extend generally orthogonal relative to the primary
airflow direction.
8. The microchannel heat exchanger of claim 1, further comprising a
gap between two headers located furthest in the direction of the
primary airflow direction.
9. The microchannel heat exchanger of claim 1, wherein no gap
exists between to headers located furthest in the direction of the
primary airflow direction.
10. An air handling unit, comprising: a primary airflow direction;
and a microchannel heat exchanger, comprising: a plurality of
microchannel tubes; and fins disposed between at least one pair of
adjacent microchannel tubes; wherein at least one of a microchannel
tube and a fin is oriented substantially parallel to the primary
airflow direction.
11. The air handling unit of claim 10, wherein the air handling
unit is a blow-through type air handling unit.
12. The air handling unit of claim 10, wherein the air handling
unit is a pull-through type air handling unit.
13. The air handling unit of claim 10, wherein the microchannel
heat exchanger is oriented as an A-coil.
14. The air handling unit of claim 10, wherein the microchannel
heat exchanger is oriented as a V-coil.
15. The air handling unit of claim 10, wherein the microchannel
heat exchanger further comprises a header extending generally
orthogonal relative to the primary airflow direction.
16. The air handling unit of claim 10, wherein the microchannel
heat exchanger further comprises a header extending generally at
angle between orthogonal and parallel relative to the primary
airflow direction.
17. The air handling unit of claim 10, both the microchannel tubes
and the fins are oriented substantially parallel to the primary
airflow direction.
18. The air handling unit of claim 10, wherein at least one of the
microchannel tubes is oriented to carry refrigerant in a direction
generally transverse relative to the primary airflow direction and
further oriented to present a minimal footprint area when viewed in
a direction parallel to the primary airflow direction while
maintaining the orientation of refrigerant travel.
19. The air handling unit of claim 10, wherein a footprint of the
microchannel tubes is maximized when viewed in a direction
substantially transverse relative to the primary airflow
direction.
20. The air handling unit of claim 10, wherein a footprint of the
microchannel tubes is minimized when viewed in direction parallel
to a direction in which the microchannel tubes carry refrigerant.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority under 35 U.S.C.
119(e) to U.S. Provisional Patent Application No. 61/762,759 filed
on Feb. 8, 2013 by Means and entitled "Microchannel Heat
Exchanger," the disclosure of which is hereby incorporated by
reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
REFERENCE TO A MICROFICHE APPENDIX
[0003] Not applicable.
BACKGROUND
[0004] Heating, ventilation, and/or air conditioning (HVAC) systems
may generally be used in residential and/or commercial structures
to provide heating and/or cooling to climate-controlled areas
within these structures. Some HVAC systems may comprise a
microchannel heat exchanger. Some microchannel heat exchangers may
comprise a plurality of microchannel tubes and/or fins that are
oriented at an angle relative to a primary direction of airflow
across the tubes and/or fins. In some cases, the angled orientation
may cause an undesirable pressure drop across the microchannel heat
exchanger.
SUMMARY
[0005] In some embodiments of the disclosure, a microchannel heat
exchanger is disclosed as comprising a plurality of microchannel
tubes and fins disposed between at least one pair of adjacent
microchannel tubes, wherein at least one of a microchannel tube and
a fin is oriented substantially parallel to a primary airflow
direction of the microchannel heat exchanger.
[0006] In other embodiments of the disclosure, an air handling unit
is disclosed as comprising a primary airflow direction and a
microchannel heat exchanger comprising a plurality of microchannel
tubes and fins disposed between at least one pair of adjacent
microchannel tubes, wherein at least one of a microchannel tube and
a fin is oriented substantially parallel to the primary airflow
direction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] For a more complete understanding of the present disclosure
and the advantages thereof, reference is now made to the following
brief description, taken in connection with the accompanying
drawings and detailed description, wherein like reference numerals
represent like parts.
[0008] FIG. 1 is a schematic diagram of an HVAC system according to
an embodiment of the disclosure;
[0009] FIG. 2 is a schematic front view of the indoor unit of FIG.
1 comprising a microchannel heat exchanger according to an
embodiment of the disclosure;
[0010] FIG. 3 is a top view of the microchannel heat exchanger of
FIG. 2;
[0011] FIG. 4 is a side view of the microchannel heat exchanger of
FIG. 2;
[0012] FIG. 5 is a front view of the microchannel heat exchanger of
FIG. 2 with the headers removed;
[0013] FIG. 6 is a partial cutaway oblique view of a plurality of
microchannel tubes of the outdoor heat exchanger according to an
embodiment of the disclosure;
[0014] FIG. 7 is a top view of a microchannel heat exchanger
according to an alternative embodiment of the disclosure; and
[0015] FIG. 8 is a front view of the microchannel heat exchanger of
FIG. 7.
DETAILED DESCRIPTION
[0016] In some cases, it may be desirable to provide a microchannel
heat exchanger in a heating, ventilation, and/or air-conditioning
(HVAC) system. Some microchannel heat exchangers may comprise
microchannel tubes and/or fins that may be oriented relative to a
primary direction of airflow in a manner that unnecessarily
requires more energy to be consumed to move air through the
microchannel heat exchanger. Some systems and methods of this
disclosure may provide microchannel heat exchangers and/or air
handling units comprising microchannel heat exchangers in which the
microchannel tubes and/or fins of the microchannel heat exchangers
are oriented relative to a primary direction of airflow in a manner
selected to minimize a pressure drop across the microchannel heat
exchanger. This disclosure further contemplates microchannel heat
exchangers and/or air handling units comprising microchannel heat
exchangers in which the microchannel tubes and/or fins of the
microchannel heat exchangers are oriented substantially parallel
relative to a primary direction of airflow to minimize a pressure
drop across the microchannel heat exchanger. In some embodiments,
the charge tolerant microchannel heat exchanger may be used in an
indoor unit and/or an outdoor unit of an HVAC system, including,
but not limited to, a heat pump system.
[0017] Referring now to FIG. 1, a schematic diagram of an HVAC
system 100 is shown according to an embodiment of the disclosure.
HVAC system 100 generally comprises an indoor unit 102, an outdoor
unit 104, and a system controller 106. The system controller 106
may generally control operation of the indoor unit 102 and/or the
outdoor unit 104. As shown, the HVAC system 100 is a so-called heat
pump system that may be selectively operated to implement one or
more substantially closed thermodynamic refrigeration cycles to
provide a cooling functionality and/or a heating functionality.
[0018] Indoor unit 102 generally comprises an indoor heat exchanger
108, an indoor fan 110, and an indoor metering device 112. Indoor
heat exchanger 108 is a plate fin heat exchanger configured to
allow heat exchange between refrigerant carried within internal
tubing of the indoor heat exchanger 108 and fluids that contact the
indoor heat exchanger 108 but that are kept segregated from the
refrigerant. In other embodiments, indoor heat exchanger 108 may
comprise a spine fin heat exchanger, a microchannel heat exchanger,
or any other suitable type of heat exchanger.
[0019] The indoor fan 110 is a centrifugal blower comprising a
blower housing, a blower impeller at least partially disposed
within the blower housing, and a blower motor configured to
selectively rotate the blower impeller. In other embodiments, the
indoor fan 110 may comprise a mixed-flow fan and/or any other
suitable type of fan. The indoor fan 110 is configured as a
modulating and/or variable speed fan capable of being operated at
many speeds over one or more ranges of speeds. In other
embodiments, the indoor fan 110 may be configured as a multiple
speed fan capable of being operated at a plurality of operating
speeds by selectively electrically powering different ones of
multiple electromagnetic windings of a motor of the indoor fan 110.
In yet other embodiments, the indoor fan 110 may be a single speed
fan.
[0020] The indoor metering device 112 is an electronically
controlled motor driven electronic expansion valve (EEV). In
alternative embodiments, the indoor metering device 112 may
comprise a thermostatic expansion valve, a capillary tube assembly,
and/or any other suitable metering device. The indoor metering
device 112 may comprise and/or be associated with a refrigerant
check valve and/or refrigerant bypass for use when a direction of
refrigerant flow through the indoor metering device 112 is such
that the indoor metering device 112 is not intended to meter or
otherwise substantially restrict flow of the refrigerant through
the indoor metering device 112.
[0021] Outdoor unit 104 generally comprises an outdoor heat
exchanger 114, a compressor 116, an outdoor fan 118, an outdoor
metering device 120, and a reversing valve 122. Outdoor heat
exchanger 114 is a microchannel heat exchanger configured to allow
heat exchange between refrigerant carried within internal passages
of the outdoor heat exchanger 114 and fluids that contact the
outdoor heat exchanger 114 but that are kept segregated from the
refrigerant. In other embodiments, outdoor heat exchanger 114 may
comprise a plate fin heat exchanger, a spine fin heat exchanger, or
any other suitable type of heat exchanger.
[0022] The compressor 116 is a multiple speed scroll type
compressor configured to selectively pump refrigerant at a
plurality of mass flow rates. In alternative embodiments, the
compressor 116 may comprise a modulating compressor capable of
operation over one or more speed ranges, a reciprocating type
compressor, a single speed compressor, and/or any other suitable
refrigerant compressor and/or refrigerant pump.
[0023] The outdoor fan 118 is an axial fan comprising a fan blade
assembly and fan motor configured to selectively rotate the fan
blade assembly. In other embodiments, the outdoor fan 118 may
comprise a mixed-flow fan, a centrifugal blower, and/or any other
suitable type of fan and/or blower. The outdoor fan 118 is
configured as a modulating and/or variable speed fan capable of
being operated at many speeds over one or more ranges of speeds. In
other embodiments, the outdoor fan 118 may be configured as a
multiple speed fan capable of being operated at a plurality of
operating speeds by selectively electrically powering different
ones of multiple electromagnetic windings of a motor of the outdoor
fan 118. In yet other embodiments, the outdoor fan 118 may be a
single speed fan.
[0024] The outdoor metering device 120 is a thermostatic expansion
valve. In alternative embodiments, the outdoor metering device 120
may comprise an electronically controlled motor driven EEV similar
to indoor metering device 112, a capillary tube assembly, and/or
any other suitable metering device. The outdoor metering device 120
may comprise and/or be associated with a refrigerant check valve
and/or refrigerant bypass for use when a direction of refrigerant
flow through the outdoor metering device 120 is such that the
outdoor metering device 120 is not intended to meter or otherwise
substantially restrict flow of the refrigerant through the outdoor
metering device 120.
[0025] The reversing valve 122 is a so-called four-way reversing
valve. The reversing valve 122 may be selectively controlled to
alter a flow path of refrigerant in the HVAC system 100 as
described in greater detail below. The reversing valve 122 may
comprise an electrical solenoid or other device configured to
selectively move a component of the reversing valve 122 between
operational positions.
[0026] The system controller 106 may generally comprise a
touchscreen interface for displaying information and for receiving
user inputs. The system controller 106 may display information
related to the operation of the HVAC system 100 and may receive
user inputs related to operation of the HVAC system 100. However,
the system controller 106 may further be operable to display
information and receive user inputs tangentially and/or unrelated
to operation of the HVAC system 100. In some embodiments, the
system controller 106 may not comprise a display and may derive all
information from inputs from remote sensors and remote
configuration tools. In some embodiments, the system controller 106
may comprise a temperature sensor and may further be configured to
control heating and/or cooling of zones associated with the HVAC
system 100. In some embodiments, the system controller 106 may be
configured as a thermostat for controlling supply of conditioned
air to zones associated with the HVAC system 100.
[0027] In some embodiments, the system controller 106 may also
selectively communicate with an indoor controller 124 of the indoor
unit 102, with an outdoor controller 126 of the outdoor unit 104,
and/or with other components of the HVAC system 100. In some
embodiments, the system controller 106 may be configured for
selective bidirectional communication over a communication bus 128.
In some embodiments, portions of the communication bus 128 may
comprise a three-wire connection suitable for communicating
messages between the system controller 106 and one or more of the
HVAC system 100 components configured for interfacing with the
communication bus 128. Still further, the system controller 106 may
be configured to selectively communicate with HVAC system 100
components and/or any other device 130 via a communication network
132. In some embodiments, the communication network 132 may
comprise a telephone network, and the other device 130 may comprise
a telephone. In some embodiments, the communication network 132 may
comprise the Internet, and the other device 130 may comprise a
smartphone and/or other Internet-enabled mobile telecommunication
device. In other embodiments, the communication network 132 may
also comprise a remote server.
[0028] The indoor controller 124 may be carried by the indoor unit
102 and may be configured to receive information inputs, transmit
information outputs, and otherwise communicate with the system
controller 106, the outdoor controller 126, and/or any other device
130 via the communication bus 128 and/or any other suitable medium
of communication. In some embodiments, the indoor controller 124
may be configured to communicate with an indoor personality module
134 that may comprise information related to the identification
and/or operation of the indoor unit 102. In some embodiments, the
indoor controller 124 may be configured to receive information
related to a speed of the indoor fan 110, transmit a control output
to an electric heat relay, transmit information regarding an indoor
fan 110 volumetric flow-rate, communicate with and/or otherwise
affect control over an air cleaner 136, and communicate with an
indoor EEV controller 138. In some embodiments, the indoor
controller 124 may be configured to communicate with an indoor fan
controller 142 and/or otherwise affect control over operation of
the indoor fan 110. In some embodiments, the indoor personality
module 134 may comprise information related to the identification
and/or operation of the indoor unit 102 and/or a position of the
outdoor metering device 120.
[0029] In some embodiments, the indoor EEV controller 138 may be
configured to receive information regarding temperatures and/or
pressures of the refrigerant in the indoor unit 102. More
specifically, the indoor EEV controller 138 may be configured to
receive information regarding temperatures and pressures of
refrigerant entering, exiting, and/or within the indoor heat
exchanger 108. Further, the indoor EEV controller 138 may be
configured to communicate with the indoor metering device 112
and/or otherwise affect control over the indoor metering device
112. The indoor EEV controller 138 may also be configured to
communicate with the outdoor metering device 120 and/or otherwise
affect control over the outdoor metering device 120.
[0030] The outdoor controller 126 may be carried by the outdoor
unit 104 and may be configured to receive information inputs,
transmit information outputs, and otherwise communicate with the
system controller 106, the indoor controller 124, and/or any other
device via the communication bus 128 and/or any other suitable
medium of communication. In some embodiments, the outdoor
controller 126 may be configured to communicate with an outdoor
personality module 140 that may comprise information related to the
identification and/or operation of the outdoor unit 104. In some
embodiments, the outdoor controller 126 may be configured to
receive information related to an ambient temperature associated
with the outdoor unit 104, information related to a temperature of
the outdoor heat exchanger 114, and/or information related to
refrigerant temperatures and/or pressures of refrigerant entering,
exiting, and/or within the outdoor heat exchanger 114 and/or the
compressor 116. In some embodiments, the outdoor controller 126 may
be configured to transmit information related to monitoring,
communicating with, and/or otherwise affecting control over the
outdoor fan 118, a compressor sump heater, a solenoid of the
reversing valve 122, a relay associated with adjusting and/or
monitoring a refrigerant charge of the HVAC system 100, a position
of the indoor metering device 112, and/or a position of the outdoor
metering device 120. The outdoor controller 126 may further be
configured to communicate with a compressor drive controller 144
that is configured to electrically power and/or control the
compressor 116.
[0031] The HVAC system 100 is shown configured for operating in a
so-called cooling mode in which heat is absorbed by refrigerant at
the indoor heat exchanger 108 and heat is rejected from the
refrigerant at the outdoor heat exchanger 114. In some embodiments,
the compressor 116 may be operated to compress refrigerant and pump
the relatively high temperature and high pressure compressed
refrigerant from the compressor 116 to the outdoor heat exchanger
114 through the reversing valve 122 and to the outdoor heat
exchanger 114. As the refrigerant is passed through the outdoor
heat exchanger 114, the outdoor fan 118 may be operated to move air
into contact with the outdoor heat exchanger 114, thereby
transferring heat from the refrigerant to the air surrounding the
outdoor heat exchanger 114. The refrigerant may primarily comprise
liquid phase refrigerant and the refrigerant may flow from the
outdoor heat exchanger 114 to the indoor metering device 112
through and/or around the outdoor metering device 120 which does
not substantially impede flow of the refrigerant in the cooling
mode. The indoor metering device 112 may meter passage of the
refrigerant through the indoor metering device 112 so that the
refrigerant downstream of the indoor metering device 112 is at a
lower pressure than the refrigerant upstream of the indoor metering
device 112. The pressure differential across the indoor metering
device 112 allows the refrigerant downstream of the indoor metering
device 112 to expand and/or at least partially convert to a
two-phase (vapor and gas) mixture. The two phase refrigerant may
enter the indoor heat exchanger 108. As the refrigerant is passed
through the indoor heat exchanger 108, the indoor fan 110 may be
operated to move air into contact with the indoor heat exchanger
108, thereby transferring heat to the refrigerant from the air
surrounding the indoor heat exchanger 108, and causing evaporation
of the liquid portion of the two phase mixture. The refrigerant may
thereafter re-enter the compressor 116 after passing through the
reversing valve 122.
[0032] To operate the HVAC system 100 in the so-called heating
mode, the reversing valve 122 may be controlled to alter the flow
path of the refrigerant, the indoor metering device 112 may be
disabled and/or bypassed, and the outdoor metering device 120 may
be enabled. In the heating mode, refrigerant may flow from the
compressor 116 to the indoor heat exchanger 108 through the
reversing valve 122, the refrigerant may be substantially
unaffected by the indoor metering device 112, the refrigerant may
experience a pressure differential across the outdoor metering
device 120, the refrigerant may pass through the outdoor heat
exchanger 114, and the refrigerant may reenter the compressor 116
after passing through the reversing valve 122. Most generally,
operation of the HVAC system 100 in the heating mode reverses the
roles of the indoor heat exchanger 108 and the outdoor heat
exchanger 114 as compared to their operation in the cooling
mode.
[0033] Referring now to FIG. 2, a schematic front view of the
indoor unit 102 of FIG. 1 comprising a microchannel heat exchanger
108 is shown according to an embodiment of the disclosure. The
indoor unit 102 generally comprises a blower cabinet 202 comprising
a blower assembly 110 and a heat exchanger cabinet 206 comprising a
microchannel heat exchanger 108. In some embodiments, the indoor
unit 102 may also comprise a heater cabinet 220 comprising a heater
assembly 222. In some embodiments, however, the heater assembly 222
may be disposed within the heat exchanger cabinet 206. The indoor
unit 102 may generally comprise a blow-through type air handling
unit comprising the microchannel heat exchanger 108 configured in
an A-coil arrangement. However, in alternative embodiments, the
indoor unit 102 may be a pull-through type air handling unit in
which air is pulled through the microchannel heat exchanger 108 by
a blower assembly, such as blower assembly 110, that is located
downstream relative to the microchannel heat exchanger 108.
Further, the microchannel heat exchanger 108 may alternatively be
oriented in a V-coil arrangement. In this embodiment, the blower
assembly 204 generally forces air through the indoor unit 102 and
the microchannel heat exchanger 108 in a primary airflow direction
210.
[0034] Referring now to FIGS. 3-5, top, side, and front views of
the microchannel heat exchanger 108 are shown, respectively. The
microchannel heat exchanger 108 generally comprises a plurality of
tubular headers 212 (not shown in FIG. 5) between which
microchannel tubes 214 may extend horizontally to join opposing
tubular headers 212 in fluid communication with each other via a
plurality of microchannels (shown as 224 and in FIG. 6) within each
of the microchannel tubes 214. The microchannel tubes 214 may
generally comprise a flat ribbon shape, and corrugated fins 216 may
be joined between adjacent microchannel tubes 214. In operation,
air may be forced between adjacent microchannel tubes 214 and into
contact with fins 216 to promote heat exchange between the air
moved by the blower assembly 110 and the refrigerant flowing
through the microchannels of the microchannel tubes 214.
[0035] As viewed from above in FIG. 3, it can be seen that each of
the microchannel tubes 214 and associated fins 216 are generally
oriented parallel relative to the primary airflow direction 210.
More specifically, the flat surfaces of the microchannel tubes 214
may generally be substantially parallel with respect to the primary
airflow direction 210. As a result, the pressure drop across the
microchannel heat exchanger 108 is minimized. Furthermore, the
indoor unit 102 may operate more efficiently at least because less
energy is required to move air through the microchannel heat
exchanger 108. Still further, as a result of the orientation of the
microchannel tubes 214 and/or fins 216 relative to the primary
airflow direction 210, condensation formed on the microchannel heat
exchanger 108 may be less likely to separate from the microchannel
heat exchanger 108 and become entrained in the airflow, thereby
exiting the microchannel heat exchanger 108. In some cases, the
above-described orientation of the microchannel tubes 214 and fins
216 may be described as oriented to provide a minimum footprint
area when viewed along a direction parallel to the primary airflow
direction 210 and transverse to a direction of refrigerant flow
through the microchannel tubes 214.
[0036] As viewed from the side in FIG. 4, it can be seen that a
lowest microchannel tube 214 is oriented generally to provide, in
this case, a maximum footprint area when viewed from the side. As
viewed from the front in FIG. 5, it can be seen that the
above-described orientation of the microchannel tubes 214 and fins
216 may be described as oriented to provide a minimum footprint
area when viewed along a direction transverse to the primary
airflow direction 210 and parallel to a direction of refrigerant
flow through the microchannel tubes 214. It can also be seen that a
significant gap 218 exist between the top located microchannel
tubes 214. In some cases, while the gap 218 may reduce a pressure
drop across the microchannel heat exchanger 108, because less air
may be forced through the microchannel heat exchanger 108 an
overall efficiency in transferring heat between the microchannel
heat exchanger 108 and the air may be reduced relative to a
substantially similar microchannel heat exchanger 108 comprising no
gap 218.
[0037] Referring now to FIG. 6, a partial cutaway oblique view of a
microchannel tube 214 of the microchannel heat exchanger 108 is
shown according to an embodiment of the disclosure. In some
embodiments, each microchannel tube 214 may comprise a plurality of
substantially parallel microchannels 224. The microchannels 224 may
generally connect the opposing tubular headers 212 in fluid
communication. In some embodiments, the microchannel tubes 214 may
comprise microchannels 224 that comprise substantially similar
diameters. In some embodiments, the microchannel tubes 214 may also
comprise a substantially similar number of microchannels 224. In
embodiments where the microchannel tubes 214 comprise a
substantially similar number of microchannels 224 having
substantially similar diameters, it will be appreciated that each
microchannel tube 214 may comprise substantially similar
microchannel 224 volumes in each microchannel tube 214.
[0038] Referring now to FIGS. 7 and 8, top and side views of a
microchannel heat exchanger 300 are shown, respectively according
to an alternative embodiment of the disclosure. The microchannel
heat exchanger 300 may be substantially similar to the microchannel
heat exchanger 108 insofar as it generally comprises a plurality of
headers 302 joined together in fluid communication by microchannel
tubes 304. Further, the adjacent microchannel tubes 304 may
generally be joined by corrugated fins 306. However, in this
embodiment, the headers 302 extend generally transverse to the
primary airflow direction 310 rather than in a direction comprising
both a significant directional component parallel to the primary
airflow direction 310 and a significant directional component
transverse to the primary airflow direction 310. In other words,
the headers 302 generally extend orthogonally and/or normal
relative to the primary airflow direction 310 rather than at a
sloped angle as with tubular headers 212. Further, the uppermost
located headers 302 are located substantially in abutment relative
to each other thereby eliminating the above-described significant
gap 218 present in microchannel heat exchanger 108. It will be
appreciated that the fins 216, 306 may be formed by corrugating a
sheet of fin material and thereafter cutting strips at the suitable
angles to yield the arrangements shown in FIGS. 3 and 7,
respectively.
[0039] This disclosure contemplates a variety of alternative
embodiments of microchannel heat exchangers (i.e. alternative
configurations such as single slab, W-shaped, etc.) in which at
least one of the microchannel tubes and the associated fins are
oriented to minimize resistance to an airflow therethrough. In some
embodiments, a microchannel heat exchanger 108, 300 may be provided
in an indoor unit that forces air in more than one primary airflow
direction. In such cases, to the extent that predefined portions of
the microchannel heat exchanger are to receive airflow in different
airflow directions, the microchannel tubes and/or fins of the
microchannel heat exchanger may be oriented to accommodate the
regional and/or localized primary airflow direction so that, as a
whole, an airside pressure drop across the microchannel heat
exchanger may be minimized. Further, while the microchannel heat
exchangers 108, 300 may be used in the indoor unit 102, in some
embodiments, each of the microchannel heat exchangers 108, 300 may
also be configured for use in the outdoor unit 104 of HVAC system
100. In some embodiments, microchannel heat exchanger 108 and/or
microchannel heat exchanger 300 may be substituted for heat
exchanger 114 in the outdoor unit 104 of HVAC system 100.
[0040] At least one embodiment is disclosed and variations,
combinations, and/or modifications of the embodiment(s) and/or
features of the embodiment(s) made by a person having ordinary
skill in the art are within the scope of the disclosure.
Alternative embodiments that result from combining, integrating,
and/or omitting features of the embodiment(s) are also within the
scope of the disclosure. Where numerical ranges or limitations are
expressly stated, such express ranges or limitations should be
understood to include iterative ranges or limitations of like
magnitude falling within the expressly stated ranges or limitations
(e.g., from about 1 to about 10 includes, 2, 3, 4, etc.; greater
than 0.10 includes 0.11, 0.12, 0.13, etc.). For example, whenever a
numerical range with a lower limit, Rl, and an upper limit, Ru, is
disclosed, any number falling within the range is specifically
disclosed. In particular, the following numbers within the range
are specifically disclosed: R=Rl+k*(Ru-Rl), wherein k is a variable
ranging from 1 percent to 100 percent with a 1 percent increment,
i.e., k is 1 percent, 2 percent, 3 percent, 4 percent, 5 percent, .
. . 50 percent, 51 percent, 52 percent, . . . , 95 percent, 96
percent, 97 percent, 98 percent, 99 percent, or 100 percent.
Moreover, any numerical range defined by two R numbers as defined
in the above is also specifically disclosed. Use of the term
"optionally" with respect to any element of a claim means that the
element is required, or alternatively, the element is not required,
both alternatives being within the scope of the claim. Use of
broader terms such as comprises, includes, and having should be
understood to provide support for narrower terms such as consisting
of, consisting essentially of, and comprised substantially of.
Accordingly, the scope of protection is not limited by the
description set out above but is defined by the claims that follow,
that scope including all equivalents of the subject matter of the
claims. Each and every claim is incorporated as further disclosure
into the specification and the claims are embodiment(s) of the
present invention.
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